The present invention relates to a streak-like defect inspecting method for a printed matter and device therefor, an edge region extracting method for use in the inspection and device therefor, a binary image preparing method and a device therefor, an image inputting method for use in printed matter inspection and device therefor, and a plain region selecting method and a device therefor, and more particularly to a streak-like defect inspecting method for a printed matter and a device therefor, which is preferably applied to the detection of a fine streak-like defect caused on the printed matter, an edge region extracting method for use in the inspection and device therefor, which is preferably applied to the image processing carried out in the above inspection, a binary image preparing method and device therefor, which is applied in the same manner, an image inputting method for use in printed matter inspection and device therefor, which is preferably applied to the inspection of the printing condition, with a pattern printed on a running original piece as an inspection subject, based on an image to be inspected input by a camera which is movable in the width-direction of the original piece, and a plain region selecting method and device therefor, which select a plain region from the whole pattern on a printed matter, and which is preferably applied to the inspection of the printing condition based on an image to be inspected in which the selected plain region is input as an inspection point by a partially inputting camera disposed on an inspection device.
Generally, a web-like gravure rotary press continuously carrying out the printing by transferring ink adhered to a rotary print drum while passing an original piece through between the print drum and a nip roll pressing it.
In order to realize such a continuous printing, the ink is supplied to the surface of the rotating print drum and then the surplus of the ink is scraped by the doctor blade.
When the doctor blade, however, is minutely broken for some reason, ink is permanently left, although a little, on the print drum contacting to the broken portion, thereby resulting in the continuous, but fine, streak-like printing defect, what is called the doctor streak, on the printing surface of the original piece.
FIG. 1 conceptually shows an image to be inspected input to inspect whether or not such a doctor streak is caused, and the features thereof. FIG. 1(A) shows an input image corresponding to one example of a longitudinally added image described later in detail. The image has a longitudinally continuous streak portion L and noises N on a substantially flat background. Accordingly, as there are shown in FIG. 1(B), FIG. 1(C), and FIG. 1(D) the graduation values (brightness values) obtained on lateral scan lines (I), (II), (III) shown in FIG. 1(A), the peaks P1 are found out at substantially the same position corresponding to the streak portions of all the profiles, and the peaks Pn resulting from the noises N are found out at the different positions.
Conventionally, printed matters have been inspected by inputting an image of a pattern to be printed, by photographing means such as a CCD camera and then detecting printing defects through the image processing of the input image.
There is known that the image processing used for detecting such printing defects includes the application of a variety of differential operators for detecting lines from the input image, and the techniques of the Hough transformation, the pattern recognition, and the like.
However, according to the above-mentioned line detecting method of the conventional image processing, it is difficult to discriminate and then detect the edge of the pattern and the streak-like defect from the image including the input pattern. Moreover, many of streak-like defects, such as the doctor streaks, extending in the same direction are low in the contrast between the streak portion and the surroundings, which provides problems that it is difficult to detect the lines, and more difficult to detect them when noises are included in the image.
Moreover, the image processing for use in such printing defect detection includes the edge extraction for detecting the edge as the density boarder of the image from the input image. This edge extraction is executed by applying a variety of the differential operators to the image data comprising the respective pixel values of the input image, and further such operators include the Prewitt operator and the Sobel operator for a primary differential, the Laplacean operator for a second differential, and the like.
However, the above-mentioned edge detecting method according to the conventional image processing undesirably extracts the edge for all the pattern portion in the input image; therefore, applying it to the printing defect inspection carried out based on the input image results in the misjudgment.
In other words, in order to detect only the printing defects by preparing a mask for excluding the edge portion from the input image to be inspected and then applying the mask to the image to be inspected, applying the above-mentioned operators to the mask preparing processing causes, when the image to be inspected includes streak-like defects such as the doctor streaks, the defects also to be processed as is the case with the pattern. Therefore, applying the prepared mask to the above-mentioned image to be inspected causes the streaks also to be undesirably masked, which disables the streak-like defects to be detected.
The above-mentioned situation will now be described more concretely taking the conventional mask preparing method as an example.
Suppose that the image to be inspected input by the camera is schematically shown by the pattern of FIG. 2(A). The image shown in FIG. 2(A) comprises four kinds of patterns having widths of a to d, respectively, which are arranged at regular intervals e, in which the narrowest line having the width of d corresponding to the doctor streak. Further, FIG. 2(B) shows the graduation values of the respective pixels with respect to the horizontal direction of FIG. 2(A).
First, as shown in FIG. 3 as FIG. 3(C) while showing the image to be inspected in FIG. 3(A), applying the Laplacean operator or the like to the image causes the edge to be extracted; then the edge regions are set at the both sides of the edge up to several pixels.
Next, as shown in FIG. 4 while showing the respective edge regions of the above FIG. 3(C), the expansion-processing causes these regions to be enlarged toward the both sides thereof by several pixels, which brings about the condition shown in FIG. 4(D). Thereafter, the contraction-processing causes these regions to be returned to the condition which is equal in pixel number to that of FIG. 3(C), which is made into a mask image. On this occasion, subjecting the pattern of the width c in the image of FIG. 2(A) to the expansion-processing causes two of the edge regions to be connected as shown in FIG. 4(D), which connected portion is not subjected to the contraction. FIG. 5(E) shows the case in which the mask images prepared as described above are overlapped on the image to be inspected of FIG. 2(A).
As can be seen from FIG. 5, when preventing the edges of the pattern from being detected by applying the mask images prepared by the use of the conventional edge extracting method, the edge regions shown in FIG. 3(C) entirely include the doctor streak of the width d shown in FIG. 2(A), which disables the doctor streak to be detected.
Moreover, the presence of the streak portion on the input image such as the above-mentioned imaged to be inspected is expected to be judgment-processed based on the binary image prepared by binary-coding the pixel values. As to the binary-coding processing method of preparing the binary image used at that occasion, there is used as the most general method a fixed threshold value processing method of binary-coding the respective pixel values of the image by the use of a fixed threshold value.
Alternatively, there is known the so-called P tile method which is used when the ratio P (rate of pixel) of area occupied by the subject to be binary-coded to the background is previously known.
According to the P tile method, when determining the threshold value T for the input-image, shown FIG. 6(A), having a distribution profile of the graduation values of one line, the binary-coding is carried out by determining the threshold value T so as to equalize the rate P of the pixels to the area ratio P of the subject to be detected on the assumption that the rate P of the pixels which are turned on in the binary image is already known, for example, by the distribution of the pixel values of 1 (ON) and 0 (OFF) for one line of the corresponding binary image shown in FIG. 6(B).
Still alternatively, there are known the methods called the moving average method of determining the threshold values every pixels, and the partial image dividing method of dividing the whole image into a plurality of grid-like partial images and then determining the threshold values every partial image.
However, the above-mentioned fixed threshold value processing method has a problem that the threshold values are difficult to be suitably determined and then the subject streak portion and the background are difficult to be correctly separated from each other. This is conceptually shown in FIG. 7. In the case of the binary-coding for the purpose of extracting a streak portion L from an input image having a streak portion L longitudinally extending and noises N, which is the same as that of FIG. 1(A), setting the threshold value to a value less than a suitable value causes the pixels of the streak portion to be turned on as shown by the binary image (output image) of FIG. 7(B), but causes almost the pixels of the noises also to be turned on, which makes it difficult to distinguish between the both, whereas setting it to a higher value disables the pixels of the streak portion to be turned on, which provides a binary image which is highlighted in only noise.
Moreover, the P tile method which automatically determines the threshold value has a problem that the subject and the background cannot be separated from each other when the area of the subject to be detected is not previously known or the area of the subject to be detected is varied. This problem will now be described with reference to FIG. 8 which conceptually shows the results of the binary-coding processing obtained when subjecting the input image similar to that of FIG. 1(A) to the P tile method.
In the case of subjecting the input image of FIG. 8(A) to the P tile method on the assumption that the number of the pixels included in the streak portion is constant, the threshold value is set to a low value when the number of pixels for use in the area calculation for calculating the threshold value is more than that of the actual streak portion, which causes much noise to be extracted as shown in FIG. 8(B). On the contrary, when the number of the pixels for use in the area calculation is less than that of the streak portion, the threshold is raised, thereby disabling the streak portion to be extracted as shown in FIG. 8(C), but enabling only the noises N each having the large graduation value to be extracted.
So long as the noises, which have higher graduation values than the streak portion, but not less in the number of the pixels than the streak portion, exist on the input image even if the number of the pixels for use in the area calculation is set to an appropriate value, that is, the sum of the number of the streak portions and xcex1, the pixels of the streak portion cannot be correctly binary-coded. This provides a problem that when the input image has such noises partially misdistributed and then locally concentrated on the input image, the locally concentrated noises and the like are extracted as shown by a circle in FIG. 8(D), which provides a problem that the subject streak portion cannot be correctly extracted. By inputting the image with the input range limited to a certain range in the subject pattern results in the high resolution inspection.
Further, the moving average method of dynamically processing the threshold value requires a long time to determine the threshold every pixel compared with the fixed threshold value processing method and the P tile method. Also, the partial image dividing method is to calculate the threshold value every pixel with respect to the respective grid-like partial images, but not so much as the moving average method, which is led to a problem that a longer processing time is required in the same manner.
As described above, the image inputting method by using the camera, which is applied to the inspection of the pattern being printed on the printer by the use of the visual check or an automatic inspection device includes a method of selecting and then inputting, by one CCD camera traversing (moving) in the width-direction, a part of the whole pattern as a photographing point from the whole pattern, corresponding to one round of the subject print drum, of the printed original piece w running in the arrow direction, as conceptually shown in FIG. 9. Thus inputting the image with the input range limited to a certain range in the subject pattern results in the high resolution inspection.
When thus inputting the image by the above-mentioned CCD camera in order to inspect a part of the pattern being printed on the printer by the use of the visual check or the inspection device, a method of determining and photographing the photographing point to be photographed, from the whole pattern includes the following three manners:
(1) To previously register the photographing points at specified fixed positions (six points with respect to the width-direction, in FIG. 10) for the whole pattern without being limited to the head, although the example in which the photographing point is set to the head is shown in FIG. 10, and then to move the camera in turn to automatically photograph there.
(2) To determine the photographing point at positions selected at random for the whole pattern, as shown in FIG. 11, and then photograph there.
(3) To move the photographing point manually and then photograph there.
However, the image inputting method related to the above items (1) to (3) which photographs a part of the whole pattern has the following problems:
In the case of the method of previously manually registering the photographing point as described in the above item (1), many points to be inspected makes the registering work difficult.
In the case of the method of determining the photographing points at random as described in the above item (2), the location which is not suitable for the photographing may be photographed, thereby degrading the inspection efficiency.
In the case of the method of moving the photographing point manually as described in the above item (3), one location to be inspected provides no problem, whereas many locations to be inspected requires the operation every movement, which degrades the efficiency.
Particularly, according to the methods of the items (1),and (2), the individual pattern existing on the subject to be inspected does not considered, which raises the possibility that a part of the pattern enters into the image to be inspected input from the determined inspection point. Accordingly, subjecting such an image to be inspected to the image processing in order to detect the fine defects provides a problem that the patterns included in the image to be inspected results in the false inspection.
Besides, in order to avoid the problem, carrying out the process of preventing the false inspection, e.g. excluding the pattern portion from the input image to be inspected, possibly causes the signals corresponding to the defects to be excepted, which provides a problem that the above prevention process unexpectedly leaves the fine defects undetected.
The present invention is made to solve the above conventional problems. It is therefore a first object of the present invention to provide a streak-like defect inspecting method for a printed matter and device therefor, which are capable of surely detect streak-like fine defects of low contract from an image to be inspected including patterns.
Further, it is a second object of the present invention to provide a streak-like defect inspecting method for a printed matter and device therefor, which are capable of detecting streak-like defects, which are low in detecting sensitivity for monochromatic images, at high accuracy when processing an image to be inspected of a color image as monochromatic images of frames of R, G, B, respectively.
Moreover, it is a third object of the present invention to provide an edge region extracting method for use in streak-like defect inspection and device therefor, which are capable of preventing the edge from being included in an edge region extracted from an image to which printing patterns and the like are input, only when a flat portion of an image signal corresponding to the pattern and the like has a width of not more than a predetermined value.
Besides, it is a fourth object of the present invention to provide a binary image preparing method for use in streak-like defect inspection and device therefor, which are capable of easily and surely preparing an image having the binary-coded streak portion from the image in which a streak portion continuing substantially in the same direction exist on a flat background, even if the image includes noises.
Also, it is a fifth object of the present invention to provide a streak-like defect inspecting method for a printed matter and device therefor, which are capable of surely detect streak-like fine defects of low contrast from an image to be inspected including patterns, by the use of the above-mentioned binary image preparing technique.
Further, it is a sixth object of the present invention to provide an image inputting method for use in printed matter inspection and device therefor, which are capable of, even when there are many photographing points to be input on the pattern, easily and surely inputting a pattern portion located at the points.
Furthermore, it is a seventh object of the present invention to provide a plain region selecting method for use in printed matter inspection and device therefor, which are capable of inputting a portion of the pattern having a low density difference as an image to be inspected, from the whole pattern on the printed matter, so as to prevent a pattern portion included in the input image to be inspected, from resulting in the false detection of the fine defects.
The present invention provides a streak-like defect inspecting method for a printed matter, which detects a streak-like defect caused on the printed matter, from an image to be inspected input on the printed matter, characterized by comprising: a pattern excepting step of exception-processing a pattern portion from the image to be inspected; a streak emphasizing step of emphasis-processing a streak portion existing on the exception-processed image; and a judging step of judging a streak-like defect based on the emphasis-processed image, which causes the above-mentioned first object to be resolved.
The present invention provides a streak-like defect inspecting device for a printed matter, which detects a streak-like defect caused on the printed matter, from an image to be inspected input on the printed matter, characterized by comprising: a pattern excepting means for exception-processing a pattern portion from the image to be inspected; a streak emphasizing means for emphasis-processing a streak portion existing on the exception-processed image; and a judging means for judging a streak-like defect based on the emphasis-processed image, which causes the above-mentioned first object to be resolved.
The present invention provides a streak-like defect inspecting method for a printed matter, which detects a streak-like defect caused on the printed matter, from a color image to be inspected input on the printed matter, characterized by comprising: a step of separating the input image to be inspected to monochromatic images of respective frames of R, G, B; a step of subjecting the respective monochromatic images to a predetermined image processing, respectively; a step of composing the respective image-processed monochromatic images to prepare a composed image; and a step of judging the presence of the streak-like defect based on the composed image, which causes the above-mentioned second object to be resolved.
The present invention provides a streak-like defect inspecting device for a printed matter, which detects a streak-like defect caused on the printed matter, from a color image to be inspected input on the printed matter, characterized by comprising: means for separating the input image to be inspected to monochromatic images of respective frames of R, G, B; means for subjecting the respective monochromatic images to a predetermined image processing, respectively; means for composing the respective image-processed monochromatic images to prepare a composed image; and means for judging the presence of the streak-like defect based on the composed image, which causes the above-mentioned second object to be resolved.
The present invention provides an edge region extracting method which extracts an edge region based on the edge which is rapidly changed in pixel value with respect to at least one of horizontal direction and vertical direction of an input image, characterized in that when there is no change of the pixel value or width of a small flat portion is not more than a predetermined value, edges positioned at both ends of the flat portion are prevented from being included in the edge regions; and otherwise, the edges are included in the edge regions, which causes the above-mentioned third object to be resolved.
The present invention provides an edge region extracting device which extracts an edge region based on the edge which is rapidly changed in pixel value with respect to at least one of horizontal direction and vertical direction of an input image, characterized in that the device comprises: means for inputting an image related to the subject; means for setting as a parameter for extracting the edge region at least a pixel number L of defining a position used for comparing pixel values and an edge-to-edge pixel number W of defining such a maximum width of a flat portion as to prevent the edge from being included in the edge region; means for comparing pixel values located apart from the subject image in opposite directions by a distance corresponding to L pixels, respectively, and extracting, as the edge region, such a subject image as to cause the compared difference to exceed a predetermined threshold value; means for calculating such an expansion pixel number N as to prevent both the edge regions from being connected, when expanding widths of a pair of the edge regions extracted for the flat portion having a width of the edge-to-edge pixel number W, with one pixel as a unit, respectively, and calculating such a contraction pixel number P as to cause the expanded edge regions to contract; means for expanding the widths of all the edge regions, which are extracted from the input image, by N pixels at a time at both sides thereof; and means for causing the widths of the expanded edge regions to contract by P pixels at a time at both sides thereof, which causes the above-mentioned edge region extracting method to be executed.
In other words, the present invention comprises the steps of inputting the image, subjecting the input image to the edge region extraction-processing, and outputting the extracted image including the resultant edge region.
The input image as the subject of the present invention may comprises any one of a binary image, a multivalued monochromatic image, and a color image. Further, the above edge region extraction-processing comprises three of (A) extraction-processing of only vertical directionwise edges, (B) extraction-processing of only horizontal directionwise edges, and (C) simultaneous extraction-processing of horizontal and vertical directionwise edges. Further, the above output image, which comprises a two dimensional binary image, is output with the edge region and the others distinguished from each other by e.g. assuming xe2x80x9c1 (or ON)xe2x80x9d to indicate the edge region and xe2x80x9c0 (or OFF)xe2x80x9d to indicate the others, and vice versa.
Moreover, the relationship between the edge region extracted according to the present invention and the input image will be described in brief while taking the case of the image signal comprising a horizontal one dimensional pixel values (graduation value) shown in FIG. 12.
FIG. 12(A) shows the case of the image in which light lines are vertically displayed on a dark background, whereas FIG. 12(B) shows the reverse case. Any one of the drawings shows that the edge is formed on the pixels which are abruptly changed in pixel value and-then exists on the boarder between one flat portion which is not changed so much in pixel value and another flat portion which is different in brightness from the one flat portion.
According to the present invention, the edge region is extracted so as to include the edge therein, as shown by half-tone dot meshing in FIG. 12, when the number of the pixels between both the edges is larger than the W value, whereas the edge region is extracted so as not to include the edge therein or no edge region is extracted at all when not larger than the W value, as described later.
As a result, it is possible to clearly distinguish very thin lines such as doctor streaks and usual patterns including the other lines; therefore, preparing a mask image based on the extracted edge region and then applying it to the printing inspection enables e.g. the doctor streaks to be surely detected.
The above-mentioned FIG. 12 corresponds to a vertical edge being extracted, as shown in FIG. 13 (A). However, changing the processing direction by 90xc2x0 enables a horizontal edge to be extracted, as shown in FIG. 13(B), and further, carrying out the vertical process and the horizontal one simultaneously enables both of the horizontal and the vertical edge regions to be simultaneously extracted.
The present invention provides a binary image preparing method for use in streak-like defect inspection, characterized by comprising: a step of inputting an image in which a streak portion continuing substantially in a same direction is expected to exist; a step of dividing the input image into continuous partial images each having a width of not less than one line and perpendicular to the streak portion; and a step of binary-coding the respective pixels by subjecting each of the divided partial images to the P tile method, which causes the above-mentioned fourth object to be resolved.
The present invention provides a binary image preparing device for use in streak-like defect inspection, characterized by comprising: means for inputting an image in which a streak portion continuing substantially in a same direction is expected to exist; means for dividing the input image into continuous partial images each having a width of not less than one line and perpendicular to the streak portion; and means for binary-coding the respective pixels by subjecting each of the divided partial images to the P tile method, which causes the above-mentioned fourth object to be resolved.
According to the present invention, the P tile method which realizes the binary-coding accurately and in a short time, if the area of the ON pixels exposed on binary-coding is previously known, is applied to the partial image comprising one or more lines perpendicular to the streak portion generating direction on the assumption that the number of the pixels to be turned on (area) is the number of the pixels included in the streak portion or a constant near thereto, which enables the streak portions existing on the respective partial images to be binary-coded accurately and in a relatively short time even if the input image has noises.
The above matter will now be described while taking the case of the input image in which the noises each having a large graduation value are locally concentrated, from which the conventional P tile method can merely obtain the binary-coded image shown in FIG. 8(D). On about upper ⅓ of the region including the noises are many partial images having non-binary-coded streak portion as before, whereas on about lower ⅔ of the region are many partial images having the noises of not more than a predetermined value and binary-coded streak portions, which enables the streak portions to be binary-coded continuously substantially in the same direction as the whole input image; although discontinuous portions are included. This enables the binary image, in which the streak portion continuing substantially in the same direction is shown clearly, to be easily and surely prepared.
The present invention provides a streak-like defect inspecting method for a printed matter, which detects a streak-like defect caused on the printed matter, from an image to be inspected input on the printed matter, characterized by comprising: a pattern excepting step of exception-processing a pattern portion from the image to be inspected; a streak emphasizing step of emphasis-processing a streak portion existing on the exception-processed image; a step of inputting the emphasis-processed image in which a streak portion continuing substantially in the same direction is expected to exist; a step of dividing the input image into continuous partial images each having a width of not less than one line and perpendicular to the streak portion; a step of binary-coding the respective pixels by subjecting each of the divided partial images to the P tile method; and a step of judging the streak-like defect based on the binary-coded image, which causes the above-mentioned fifth object to be resolved.
The invention provides a streak-like defect inspecting device for a printed matter, which detects a streak-like defect caused on the printed matter, from an image to be inspected input on the printed matter, characterized by comprising: a pattern excepting means for exception-processing a pattern portion from the image to be inspected; a streak emphasizing means for emphasis-processing a streak portion existing on the exception-processed image; means for inputting the emphasis-processed image in which a streak portion continuing substantially in the same direction is expected to exist; means for dividing the input image into continuous partial images each having a width of not less than one line and perpendicular to the streak portion; means for binary-coding the respective pixels by subjecting each of the divided partial images to the P tile method; and means for judging the streak-like defect based on the binary-coded image, which causes the above-mentioned fifth object to be resolved.
The present invention provides an image inputting method for use in printed matter inspection, which is applied to the inspection of the printing condition, with a pattern printed on a running original piece by a print drum as an inspection subject, based on a partial image to which a part of the pattern is input by a partially inputting camera which is capable of being moved in the width-direction of the original piece by a moving mechanism, characterized by comprising: a step of inputting whole image including whole pattern by a wholly inputting camera disposed apart from the partially inputting camera by a predetermined distance in such a direction as that the original piece flows; a step of coordinating, based on the relationship between a position, on the whole image, of the partial image which is capable of being input by the partially input camera and a width-directionwise reference point set on the whole image, the width-directionwise position on the whole image and the width-directionwise position on the moving mechanism with each other, when the inputting camera is located on an origin set on the moving mechanism; a step of positioning and then setting a photographing point, which is to be input by the partially inputting camera, on the whole image; a step of calculating a width-directionwise pixel number between the set photographing point and the width-directionwise reference point on the whole image; a step of multiplying the calculated width-directionwise pixel number by a width-directionwise resolution of the whole image to calculate the width-directionwise moving amount on the moving mechanism; a step of moving the partially inputting camera up to a target position corresponding to the width-directionwise moving amount; and a step of inputting the partial image at an arbitrary timing by the partially inputting camera moved up to the target position, which causes the above-mentioned sixth object to be resolved.
The present invention provides an image inputting device for use in printed matter inspection, which is applied to the inspection of the printing condition, with a pattern printed on a running original piece by a print drum as an inspection subject, based on a partial image to which a part of the pattern is input by a partially inputting camera which is capable of being moved in the width-direction of the original piece by a moving mechanism characterized by comprising: a wholly inputting camera for inputting whole image including whole pattern, disposed apart from the partially inputting camera by a predetermined distance in such a direction as that the original piece flows; means for coordinating, based on the relationship between a position, on the whole image, of the partial image which is capable of being input by the partially input camera and a width-directionwise reference point set on the whole image, the width-directionwise position on the whole image and the width-directionwise position on the moving mechanism with each other, when the partially inputting camera is located on an origin set on the moving mechanism; means for positioning and then setting a photographing point, which is to be input by the partially inputting camera, on the whole image; means for calculating a width-directionwise pixel number between the set photographing point and the width-directionwise reference point on the whole image; means for multiplying the calculated width-directionwise pixel number by a width-directionwise resolution of the whole image to calculate the width-directionwise moving amount on the moving mechanism; means for moving the partially inputting camera up to a target position corresponding to the width-directionwise moving amount; and means for inputting the partial image at an arbitrary timing by the partially inputting camera moved up to the target position, which causes the above-mentioned sixth object to be resolved.
In the image inputting method according to the present invention, the whole image including the whole pattern is input by the wholly inputting camera, and then the position on the whole image and the actual position of the partially inputting camera (position on the hardware) are coordinated based on the relationship between the whole image and the partial image input by the partially inputting camera, which enables the partial image of the photographing point to be easily input by only setting the photographing point to be input by the partial inputting camera to a predetermined width-directionwise position on the whole image by a pointing device or the like.
The present invention provides the above image inputting method characterized by comprising: a step of calculating a reference inputting timing in which the partially inputting camera is capable of inputting a pattern portion positioned at the flow-directionwise reference point on the whole image, based on a flow-directionwise distance between the wholly inputting camera and the partially inputting camera, and a print drum circumferential length; a step of positioning and then setting a photographing point, to be input by the partially inputting camera, on the whole image also with respect to a flow direction other than the width-direction; a step of calculating the flow-directionwise pixel number between the set photographing point and the flow-directionwise reference point; a step of calculating a waiting time from the reference inputting timing based on the actual distance obtained by multiplying the calculated flow-directionwise pixel number by the flow-directionwise resolution of the whole image; and a step of inputting the partial image at a timing after the elapse of the waiting time from the reference input timing, based on the partially inputting camera moved up to the target position by the moving mechanism, which enables the photographing point to be set in the flow direction.
The present invention provides the above image inputting device characterized by comprising: means for calculating a reference inputting timing in which the partially inputting camera is capable of inputting a pattern portion positioned at the flow-directionwise reference point on the whole image, based on a flow- directionwise distance between the wholly inputting camera and the partially inputting camera, and a print drum circumferential length; means for positioning and then setting a photographing point, to be input by the partially inputting camera, on the whole image also with respect to a flow direction other than the width-direction; means for calculating the flow-directionwise pixel number between the set photographing point and the flow-directionwise reference point; means for calculating a waiting time from the reference inputting timing based on the actual distance obtained by multiplying the calculated flow-directionwise pixel number by the flow-directionwise resolution of the whole image; and means for inputting the partial image at a timing after the elapse of the waiting time from the reference input timing, based on the partially inputting camera moved up to the target position by the moving mechanism, which enables the photographing point to be set in the flow direction.
The present invention provides an image inputting method for use in printed matter inspection, which is applied to the inspection of the printing condition, with a pattern printed on a running original piece by a print drum as an inspection subject, based on a partial image to which a part of the pattern is input by a partially inputting camera which is capable of being moved in the width-direction of the original piece by a moving mechanism, characterized by comprising: a step of inputting a whole image including the whole pattern as a reference image by a wholly inputting camera disposed apart from the partially inputting camera by a predetermined distance in a direction that the original piece flows; a step of coordinating, based on the relationship between a position, on the reference image, of the partial image which is capable of being input by the partially input camera and a width-directionwise reference point set on the reference image, the width-directionwise position on the reference image and the width-directionwise position on the moving mechanism with each other, when the partially inputting camera is located on an origin set on the moving mechanism; a step of positioning and then setting a photographing point, which is to be input by the partially inputting camera, on the reference image; a step of calculating a width-directionwise pixel number between the set photographing point and the width-directionwise reference point on the reference image; a step of multiplying the calculated width-directionwise pixel number by a width-directionwise resolution of the reference image to calculate the width-directionwise moving amount on the moving mechanism; a step of moving the partially inputting camera up to a target position corresponding to the width-directionwise moving amount; and a step of inputting the partial image at an arbitrary timing by the partially inputting camera moved up to the target position; a step of inputting the whole image as the newest image suitably by the wholly inputting camera; and a step of amending the width-directionwise moving amount of the partially imputing camera based on the width-directionwise difference between the newest image and the reference image, which causes the above-mentioned sixth object to be resolved.
The present invention provides an image inputting device for use in printed matter inspection, which is applied to the inspection of the printing condition, with a pattern printed on a running original piece by a print drum as an inspection subject, based on a partial image to which a part of the pattern is input by a partially inputting camera which is capable of being moved in the width-direction of the original piece by a moving mechanism, characterized by comprising: a wholly inputting camera for inputting a whole image including a whole pattern as a reference image, disposed apart from the partially inputting camera by a predetermined distance in a direction that the original piece flows; means for coordinating, based on the relationship between a position, on the reference image, of the partial image which is capable of being input by the partially input camera and a width-directionwise reference point set on the reference image, the width-directionwise position on the reference image and the width-directionwise position on the moving mechanism with each other, when the partially inputting camera is located on an origin set on the moving mechanism; means for positioning and then setting a photographing point, which is to be input by the partially inputting camera, on the reference image; means for calculating a width-directionwise pixel number between the set photographing point and the width-directionwise reference point on the reference image; means for multiplying the calculated width-directionwise pixel number by a width-directionwise resolution of the reference image to calculate the width-directionwise moving amount on the moving mechanism; means for moving the partially inputting camera up to a target position corresponding to the width-directionwise moving amount; and means for inputting the partial image at an arbitrary timing by the partially inputting camera moved up to the target position; means for inputting the whole image as the newest image suitably by the wholly inputting camera; and means for amending the width-directionwise moving amount of the partially imputing camera based on the width-directionwise difference between the newest image and the reference image, which causes the above sixth object to be resolved.
According to the present invention, the whole image including the whole pattern is input by the wholly inputting camera as a reference image, and then the position on the whole image and the actual position of the partially inputting camera (position on the hardware) are coordinated based on the relationship between the whole image (reference image) and the partial image input by the partially inputting camera, which enables the partial image of the photographing point to be easily input by only setting the photographing point to be input by partial inputting camera to a predetermined width-directionwise position on the whole image by a pointing device or the like. In addition, when there is caused an offset (difference) between the newest image and the reference image suitably compared to each other, the width-directionwise position of the partially inputting camera is amended based on the above-mentioned offset, which enables the partial image of the photographing point to be permanently accurately input even when the original piece undergoes the width-directionwise offset in time sequence, or the pattern undergoes the flow-directionwise offset.
The present invention provides the image inputting method characterized by comprising: a step of calculating a reference inputting timing in which the partially inputting camera is capable of inputting a pattern portion positioned at the flow-directionwise reference point on the reference image, based on a flow-directionwise distance between the wholly inputting camera and the partially inputting camera, and a print drum circumferential length; a step of positioning and then setting a photographing point, to be input by the partially inputting camera, on the reference image also with respect to a flow direction other than the width-direction; a step of calculating the flow-directionwise pixel number between the set photographing point and the flow-directionwise reference point, on the reference image; a step of calculating a waiting time from the reference inputting timing based on the actual distance obtained by multiplying the calculated flow-directionwise pixel number by the flow-directionwise resolution of the reference image; and a step of inputting the partial image at a timing after the elapse of the waiting time from the reference input timing, based on the partially inputting camera moved up to the target position by the moving mechanism; and a step of amending the partial image inputting timing of the partially imputing camera based on the flow-directionwise difference between the newest image and the reference image, which enables the photographing point to be set in the flow direction.
The present invention provides the image inputting device characterized by comprising: means for calculating a reference inputting timing in which the partially inputting camera is capable of inputting a pattern portion positioned at the flow-directionwise reference point on the reference image, based on a flow-directionwise distance between the wholly inputting camera and the partially inputting camera, and a print drum circumferential length; means for positioning and then setting a photographing point, to be input by the partially inputting camera, on the reference image also with respect to a flow direction other than the width-direction; means for calculating the flow-directionwise pixel number between the set photographing point and the flow-directionwise reference point, on the reference image; means for calculating a waiting time from the reference inputting timing based on the actual distance obtained by multiplying the calculated flow-directionwise pixel number by the flow-directionwise resolution of the reference image; and means for inputting the partial image at a timing after the elapse of the waiting time from the reference input timing, based on the partially inputting camera moved up to the target position by the moving mechanism; and means for amending the partial image inputting timing of the partially inputting camera based on the flow-directionwise difference between the newest image and the reference image, which causes the photographing point to be similarly set in the flow direction.
The present invention provides a plain region selecting method for use in printed matter inspection, which selects a plain region from the whole pattern on the printed matter, and which is applied to the inspection of the printing condition based on an image to be inspected in which the selected plain region is input as an inspection point by a partially inputting camera disposed on an inspection device, wherein the method comprises: a step of inputting the whole image including the printed whole pattern; a step of cutting partial images from the input whole image with the size corresponding to the image to be inspected, as a unit; a step of calculating the evaluation value representing the flatness of the brightness for the respective cut partial images; a step of selecting the partial image which is high in the flatness of the brightness therefrom based on the calculated evaluation value and then judging a predetermined number of the partial images as the inspection point on the image; and a step of outputting the position information related to the judged inspection points to the inspection device, which causes the above-mentioned seventh object to be resolved.
In other words, the present invention comprises the steps of dividing the whole image to which the whole pattern as the subject to be inspected is input, into the partial images of a predetermined size, evaluating the flatness of each of the respective partial images, judging the partial image having the high flatness as the inspection point, and then outputting the positional information of the inspection point to the inspection device, which enables the plain region having a remarkably small density difference, on the printed matter to be selected and then the image to be input. Moreover, the plain region means the region which has almost no density difference on the printed matter, or the region which is near thereto as much as possible.
The present invention provides the plain region selecting method characterized in that the evaluation value representing the flatness of the brightness comprises at least one of the maximum frequency of the brightness distribution related to the whole pixels included in the partial images, the dispersion of the brightness distribution, the brightness value of dividing the brightness distribution at a predetermined rate offsetting toward the higher brightness or the lower brightness.
The present invention provides the plain region selecting method characterized by cutting in turn all over the whole image while shifting the partial image on the whole image by one pixel at a time at least in the lateral direction.
The present invention provides a plain region selecting device for use in printed matter inspection, which selects a plain region from the whole pattern on the printed matter, and which is applied to the inspection of the printing condition based on an image to be inspected in which the selected plain region is input as an inspection point by a partially inputting camera disposed on an inspection device, wherein the device comprises: means for inputting whole image including printed whole pattern; means for cutting partial images from the input whole image with the size corresponding to the image to be inspected, as a unit; means for calculating the evaluation value representing the flatness of the brightness for the respective cut partial images; means for selecting the partial image which is high in the flatness of the brightness therefrom based on the calculated evaluation value and then judging a predetermined number of the partial images as the inspection point on the image; and means for outputting the position information related to the judged inspection points to the inspection device, which causes the above-seventh object to be resolved.
The present invention provides the plain region selecting device characterized in that the evaluation value representing the flatness of the brightness comprises at least one of the maximum frequency of the brightness distribution related to the whole pixels included in the partial images, the dispersion of the brightness distribution, the brightness value of dividing the brightness distribution at a predetermined rate offsetting toward the higher brightness or the lower brightness.
The present invention provides the plain region selecting characterized by cutting in turn all over the whole image while shifting the partial image on the whole image by one pixel at a time at least in the lateral direction.